Tricarboxylic acid-cycle enzymes and ATP pool in facultative and obligate methylotrophs: Pseudomonas J26 and Methylomonas Pl1

• Published in: Acta biochimica polonica Vol. 26; no. 4; pp. 397 - 406
• Main Authors: Michalik, J, Budohoski, L, Raczyńska-Bojanowska, K
• Format: Journal Article
• Language: English
• Published: Poland 1979
• Subjects: Adenosine Triphosphate - metabolism; Alcohol Oxidoreductases - metabolism; Aldehyde-Lyases - metabolism; Citrate (si)-Synthase - metabolism; Citric Acid Cycle; Energy Metabolism; Glutamate Dehydrogenase - metabolism; Hexosephosphates - metabolism; Isocitrate Dehydrogenase - metabolism; Isocitrate Lyase - metabolism; Ketoglutarate Dehydrogenase Complex - metabolism; Malate Dehydrogenase - metabolism; Methylococcaceae - enzymology; Pseudomonas - enzymology; Succinate Dehydrogenase - metabolism
• ISSN: 0001-527X

1. No essential differences were found in the activities of tricarboxylic acid-cycle enzymes in the newly isolated facultative methylotroph Pseudomonas J26 and obligate methylotroph Methylomonas Pl1. 2-Oxoglutarate dehydrogenase and succinate dehydrogenase were absent in Methylomonas Pl1; in Pseudomonas J26 the functioning of the cycle was imparied only on the methanol medium. Citrate synthase of both organisms showed low sensitivity to 2-oxoglutarate, NADH and ATP. 2. In both methylotrophs, methanol dehydrogenase was inhibited non-competitively by ATP: the activity was reduced by half by ATP at a concentration of 5 mM. 3. Concentration of ATP in the log-phase cultures of Methylomonas Pl1 was about twice as high as in Pseudomonas J26 (4.7 and 1.7 mumol/g dry wt., respectively). 4. Differences between the energy state of Methylomonas Pl1 and Pseudomonas J26 might be due to the higher ability of the former to oxidize methanol and/or lower energy requirement for C1 assimilation by the hexulose pathway in the obligate methylotroph.